9A single output synchronous buck regulator The IR3899AMTRPBF is a 9A easy-to-use, fully integrated synchronous buck regulator. It uses a compensation free fast Constant-On-Time (COT) control scheme, which simplifies the design effort and minimizes the bill of material (BOM). The IR3899A is offered in a small 4mm x 5mm PQFN package with excellent thermal performance.